Device For Shot-Peening A Metal Substrate, The Surface Of Which Is Predetermined By Masking Using A Screen Consisting Of A Removable Adhesive Material

ABSTRACT

The invention relates to a device for shot-peening a metal substrate, the surface of which is predetermined by masking using a screen consisting of a removable adhesive material. Said method is particularly suitable for the low-cost production of a pattern on objects such as a metal tile, trash cans, and stainless steel vases. The device includes a machine for cutting adhesive and a gun provided with a bellows, which is to be positioned on the adhesive using a sight and target that is then applied to the object.

The present invention relates to a device for etching a metal substrate which may or may not be polished beforehand.

This method is particularly suited to the creation of patterns on objects such as metal tiles, refuse containers and vases made of stainless steel with a low cost price.

Conventionally, metals and stainless steels are decorated in various ways, for example mention may be made of:

-   -   chemical attack,     -   etching,     -   rolling,     -   screen printing.

It is known that the polished finish of stainless steel is broken down into several types of finish classified according to the level of roughness: bright polish, which has a reflective appearance but in which the polishing marks are discernible, mirror finish and ultra-smooth mirror finish which achieve a brightness equivalent to a glazed mirror.

There are also screen cloth or woven decorative effects, repetitive patterns obtained by offsetting the path of the polishing brushes.

Chemical attack yields a uniformly etched appearance the depth of which is determined by the duration of the chemical attack on the unmasked surfaces.

The etching may be performed by shot peening, sandblasting, or micropeening with the use of masks. The depth of etching is uniform.

Rolling the surface using metal rolls allows geometric patterns to be embossed into the material.

Micropeening is usually performed inside a booth and it is necessary for the workpieces to be loaded and unloaded through the door of the booth, and this limits the size of the workpieces that can be decorated and makes handling more complicated.

It is therefore an object of the invention to eliminate these disadvantages.

The present invention therefore relates to a method for etching a metal substrate by micropeening, characterized in that the etched surface is determined by masking using a screen affixed beforehand to said metal substrate, the aforementioned screen being made of a removable adhesive substance.

According to one aspect of the invention, said metal substrate is polished or unpolished stainless steel.

According to another aspect of the invention, several different surface finishes can be obtained by using different glass or steel beads of different diameters.

According to another aspect of the invention, several successive markings can be achieved with superpositions of different shapes and different surface finishes.

According to another aspect of the invention, the method uses an adhesive cutting machine and a micropeening device comprising a gun fitted with a protective boot which positions itself on the adhesive, using a sight and target.

According to another aspect of the invention, said cut-out adhesive is made of PVC monomer and has a thickness of between 0.2 and 0.5 mm.

According to another aspect of the invention, the nozzle that ejects the beads inside the gun moves, driven by electric actuators.

According to another aspect of the invention, the beads are recovered by a suction pipe inside the gun casing.

The device first of all comprises an adhesive-cutting machine: the decorated shape (2) and the zone (1) to which the machine will be applied, are cut out in an adhesive (FIG. 3).

The adhesive cut-out is made of PVC monomer and has a thickness of between 0.2 and 0.5 mm.

The adhesive (1) (2) is applied by hand to the workpiece (I) (FIG. 4) using a transfer sheet which also acts as a positioning template. Air bubbles are removed using a scraper.

A gun (10) (FIG. 1), fitted with a protective boot (11), which is positioned on the adhesive using a sight (17) and the target (30), is then applied to the object (I).

To ensure that the operation is safe, a sensor (12) checks that the boot (11) is pressed firmly against the entire surface before the micropeening is allowed to commence.

The operator squeezes the trigger of the gun (13).

The nozzle (14) (FIG. 2) that ejects the steel (20) or glass beads becomes operative, driven by electric actuators (15) inside the gun, and sweeps at constant speed over the decoration surface.

The beads are recovered by a suction pipe (16) inside the gun casing.

The masked surfaces are not micropeened.

The operator releases the trigger (13), waits a few moments for the device to stop sucking up the beads (20) then removes the gun and its boot from the workpiece.

The mask (1) is removed by hand.

Several successive markings can be achieved with superpositions of different surface finishes and shapes. The decorating operations are repeated with different masks and using different micropeening parameters.

There are three sizes of mask and boot available.

Several different surface finishes can foe obtained by using different glass or steel beads of different diameters. 

1. A method for etching a metal substrate by micro peening, characterized in that the etched surface is determined by masking using a screen affixed beforehand to said metal substrate, the aforementioned screen being made of a removable adhesive substance.
 2. The method as claimed in claim 1, characterized in that said metal substrate is polished or unpolished stainless steel.
 3. The method as claimed in claim 1, characterized in that several different surface finishes can be obtained by using different glass or steel beads of different diameters.
 4. The method as claimed in claim 1, characterized in that several successive markings can be achieved with superpositions of different shapes and different surface finishes.
 5. The method as claimed in claim 1, characterized in that it uses an adhesive cutting machine and a micro peening device comprising a gun fitted with a protective boot which positions itself on the adhesive, using a sight and target.
 6. The method as claimed in claim 5, characterized in that said cut-out adhesive is made of PVC monomer and has a thickness of between 0.2 and 0.5 mm.
 7. The method as claimed in claim 5, characterized in that the nozzle that ejects the beads inside the gun moves, driven by electric actuators.
 8. The method as claimed in claim 5, characterized in that the beads are recovered by a suction pipe inside the gun casing.
 9. A method for etching a metal substrate, the method comprising: (a) applying a mask over a surface of the metal substrate such that a portion of the surface of metal substrate is covered by the mask and a portion of the surface of the metal substrate is exposed through the mask; (b) positioning a protective boot over the surface of the metal substrate to cover at least the portion of the substrate over which the mask is attached; (c) applying a sensor to the surface of the metal substrate, wherein the sensor senses the position of the protective boot; (d) positioning a nozzle of a gun within the protective boot such that the gun nozzle is exposed to at least the portion of the surface of the metal substrate exposed through the mask; and (e) ejecting beads from the gun nozzle such that the beads impact the surface of the metal substrate at a constant speed over the masked portion of the surface of the metal substrate.
 10. The method of claim 9 further comprising: positioning a suction pipe within the protective boot; and recovering beads by sucking up the beads with the suction pipe.
 11. The method of claim 9 wherein after ejecting beads from the gun nozzle, the method further comprises: removing the gun for the protective boot; removing the sensor; and removing the boot; and removing the mask.
 12. The method of claim 9 wherein after performing (a)-(e), the method comprises: (f) applying a second, different mask over the surface of the metal substrate such that a portion of the surface of metal substrate is covered by the second mask and a portion of the surface of the metal substrate is exposed through the second mask; (g) positioning the protective boot over the surface of the metal substrate to cover at least the portion of the substrate over which the second mask is applied; (h) applying the sensor to the surface of the metal substrate, wherein the sensor senses the position of the protective boot; (i) positioning the gun nozzle within the protective boot such that the gun nozzle is exposed to at least the portion of the surface of the metal substrate exposed through the second mask; and (j) ejecting beads from the gun nozzle such that the beads impact the surface of the metal substrate at a constant speed over the second masked portion of the surface of the metal substrate.
 13. The method of claim 9 wherein masking at least a portion of the metal substrate comprises by attaching a screen to the portion of the metal substrate;


14. The method of claim 13 wherein attaching a screen to the portion of the metal substrate comprises removably attaching the screen to the portion of the metal substrate.
 15. The method of claim 14 wherein removably attaching the screen to the portion of the metal substrate comprises attaching an adhesive to the portion of the metal substrate.
 16. The method of claim 15 wherein attaching an adhesive to the portion of the metal substrate comprises applying the adhesive to the portion of the metal substrate using a transfer sheet which also acts as a positioning template.
 17. The method of claim 9 wherein ejecting beads from the gun nozzle comprises one of: ejecting glass beads from the gun nozzle onto the surface of the metal substrate; or ejecting glass beads from the gun nozzle onto the surface of the metal substrate.
 18. The method of claim 9 wherein ejecting beads from the gun nozzle comprises one of:


19. The method as claimed in claim 9, wherein a plurality of masks are successively applied to the surface of the metal substrate and beads are ejected from the gun nozzle after each of the plurality of mask are applied to the surface of the metal substrate to provide the surface of the metal substrate having markings on the surface of the metal substrate wherein the markings are provided from superpositions of the successively applied plurality of masks.
 20. The method of claim 9 wherein ejecting beads from the gun nozzle on the surface of the substrate comprises sweeping the gun nozzle across the surface of the metal substrate at a constant speed using an actuator inside the gun. 